This invention relates to the neodymium laser incorporating a fluroescent converter and, more particularly, one which incorporates a dopant material which substantially enhances the spectral conversion efficiency of the fluorescent converter.
The use of fluorescent converters to increase the pumping efficiency of flash lamp pumped neodymium lasers has been suggested in the past. However, it has proved to be extremely difficult to find fluorescent converter materials which meet all of the necessary requirements for an effective converter; viz, high quantum efficiency, a very short (less than 20 microseconds) fluorescence decay time, spectral emission in the 740 to 900 nanometer region which is efficiently absorbed by neodymium and adequate reliability and durability.
Applicant however, has found, that chromium doped aluminum tungstate is extremely effective as a fluorescent converter material for enhancing the pumping efficiency of a flash lamp pumped neodymium laser. Chromium doped aluminum tungstate fluorescent converters have high quantum efficiencies; [i.e., conversions greater than 90 percent] and short fluorescence decay times--with a decay constant [1/e] of approximately sixteen (16) microseconds which make them extremely effective converters.
It is interesting to note that attempts in the past to utilize chromium doped aluminum tungstate as a laser material ended in disappointment because the material had short decay time; i.e., the emission decayed too rapidly.
The very characteristic that made chromium doped aluminum tungate undesirable as a laser material was found by applicant to be helpful in its use as a fluorescent converter in a laser system.
It is therefore a principal objective of the instant invention to provide a neodynium laser system utilizing chromium doped aluminum tungstate fluorescent converter material.
Another objective of the invention is to utilize chromium doped aluminum tungstate for converting flash lamp light outside of the neodynium pumping band wave lengths to wave lengths absorbed by the laser.
Other objectives and advantages of the instant invention will become apparent as the description of the invention proceeds.